Cytoskeletal turnover and Myosin contractility drive cell autonomous oscillations in a model of Drosophila Dorsal Closure

Oscillatory behaviour in force-generating systems is a pervasive phenomenon in cell biology. In this work, we investigate how oscillations in the actomyosin cytoskeleton drive cell shape changes during the process of Dorsal Closure, a morphogenetic event in Drosophila embryo development whereby epidermal continuity is generated through the pulsatile apical area reduction of cells constituting the amnioserosa (AS) tissue. We present a theoretical model of AS cell dynamics by which the oscillatory behaviour arises due to a coupling between active Myosin-driven forces, actin turnover and cell deformation. Oscillations in our model are cell-autonomous and are modulated by neighbour coupling, and our model accurately reproduces the oscillatory dynamics of AS cells and their amplitude and frequency evolution. A key prediction arising from our model is that the rate of actin turnover and Myosin contractile force must increase during DC in order to reproduce the decrease in amplitude and period of cell area oscillations observed in vivo. This prediction opens up new ways to think about the molecular underpinnings of AS cell oscillations and their link to net tissue contraction and suggests the form of future experimental measurements.Comment: 17 pages, 6 figures; added references, modified and corrected Figs. 1 and 3, corrected typos, expanded discussio

How the internet is shaping the Chilean scientific community: globalization and dependency

The Internet has emerged as a catalyst for global knowledge production. This is supported by its positive impacts in the First World. A progressive assessment argues that the Internet will be the elixir that brings immediate visibility and relevance to scientific communities in the periphery. Yet, Internet diffusion is often framed by past technology failures that further widen global divides. This characterizes an affliction argument. The teething argument suggests that adoption within the Third World is tentative at best with benefits unfolding over time in some regions but not others. This dissertation is a qualitative and quantitative study that tests these three technology arguments (elixir, affliction, and, teething) in a Latin American region. It considers the relationship between scientific communication, collaboration, and productivity in Chilean science, focusing on the role of Internet practice. Results are presented through the qualitative analysis of 29 video taped interviews, followed by a quantitative analysis of a communication network survey administered to 337 Chilean researchers. Qualitative findings suggest that despite Chilean regional leadership in economic output, political disruptions and a paucity of local resources motivate many researchers to seek training abroad. This creates new, exterior contacts that are maintained through email communication. These cyber links, though, may also be creating technology dependencies. Quantitative results confirm that Chilean scientists are well connected when compared to past region studies. Yet, the Chilean scientific community reports an inverse relationship between domestic and foreign contacts, mirroring the disjointed network profile found in other developing regions. Other results suggest that Chilean scientists frequently publish in foreign journals. And in contrast to findings from other developing areas, collaboration is consistently related with increased domestic publications. Although Chileans seldom report problems, those they do report are associated with working with more collaborators and having geographically heterogeneous networks. Email shows no effect toward reducing research problems; and in some cases, email is associated with more intensive reports of problems. Taken as a whole, this author\u27s findings support a teething argument for Internet influence on professional networks and activities within the Chilean scientific community

Discussing the Feasibility of Acoustic Sensors for Side Channel-aided Industrial Intrusion Detection: An Essay

The fourth industrial revolution leads to an increased use of embedded computation and intercommunication in an industrial environment. While reducing cost and effort for set up, operation and maintenance, and increasing the time to operation or market respectively as well as the efficiency, this also increases the attack surface of enterprises. Industrial enterprises have become targets of cyber criminals in the last decade, reasons being espionage but also politically motivated. Infamous attack campaigns as well as easily available malware that hits industry in an unprepared state create a large threat landscape. As industrial systems often operate for many decades and are difficult or impossible to upgrade in terms of security, legacy-compatible industrial security solutions are necessary in order to create a security parameter. One plausible approach in industry is the implementation and employment of side-channel sensors. Combining readily available sensor data from different sources via different channels can provide an enhanced insight about the security state. In this work, a data set of an experimental industrial set up containing side channel sensors is discussed conceptually and insights are derived

Los costes socioeconómicos de la diabetes mellitus

ObjetivoEvaluar el impacto económico en términos de costes directos (costes de la asistencia sanitaria) y costes indirectos (efectos sobre la producción provocados por la mortalidad y morbilidad) de la diabetes mellitus (DM) en Canarias durante el año 1998.DiseñoEl enfoque que se ha utilizado es el método del coste de la enfermedad, considerando a las personas únicamente en una esfera productiva (capital humano). Los costes directos e indirectos se han estimado utilizando los costes de la prevalencia, es decir, los costes que se producen durante el año 1998.EmplazamientoLos costes directos se han desglosado en asistencia hospitalaria, atención primaria, consultas externas, fármacos y pruebas complementarias; los costes indirectos en mortalidad anticipada y bajas laborales.Mediciones y resultados principalesEl coste total de la DM ascendió a 6.468,76 millones de pesetas (38,88 millones de e) o el equivalente a 126.168 pesetas (758,28 e) anuales por cada paciente diabético conocido. El coste directo total atribuible a la DM fue de 4.011,51 millones de pesetas (24,11 millones de e), lo que supone el 2,13% del gasto sanitario en Canarias, o el equivalente a 78.240 pesetas (470,23 e) anuales por cada paciente diabético conocido. El coste directo de la asistencia sanitaria constituyó un 62% del coste total. El coste indirecto total fue de 2.457,25 millones de pesetas (14,77 millones de e), lo que constituye un 38% del coste totalConclusionesA pesar de haberse adoptado un enfoque conservador, dado que el estudio no incluye los costes asociados con el dolor y sufrimiento, invalidez permanente y la atención en el hogar por parte de los familiares, el elevado coste socioeconómico de los pacientes con DM abre un camino hacia estudios coste-efectividad que permitan un debate más transparente sobre este tema.ObjectiveTo evaluate the economic impact in terms of the direct costs (health care costs) and the indirect costs (effects on production caused by mortality and morbidity) of diabetes mellitus (DM) in the Canary Islands (Spain) during 1998.DesignThe approach used was to study the cost of the disease through looking only at people in the productive sphere (human capital). Direct and indirect costs were calculated by using costs of prevalence, i.e. the costs caused during 1998.SettingDirect costs were broken down into hospital care, primary care, out-patient consultations, drugs and further tests; indirect costs, into premature mortality and time off work.Measurements and main resultsThe total cost of DM amounted to 6468.76 million pesetas (38.88 millio e), or the equivalent of 126 168 pesetas (758.28 e) a year for each known diabetic patient. Total direct cost of DM was 4011.51 million pesetas (24.11 million e), which amounts to 2.13% of health expenditure in the Canaries; or the equivalent of 78 240 pesetas (470.23 e) a year for each known diabetic patient. Direct cost of health care was 62% of the total cost. Total indirect cost was 2457.25 million pesetas (14.77 million e), 38% of the total cost.ConclusionsDespite the conservatism of the approach, in that the study omitted costs linked to pain and suffering, permanent disability or home care by family members, the high social and economic cost of DM patients calls for cost-effectiveness studies that would permit a more transparent debate on this question

Direct determination of the crystal field parameters of Dy, Er and Yb impurities in the skutterudite compound CeFe4_{4}P12_{12} by Electron Spin Resonance

Despite extensive research on the skutterudites for the last decade, their electric crystalline field ground state is still a matter of controversy. We show that Electron Spin Resonance (ESR) measurements can determine the full set of crystal field parameters (CFPs) for the Th cubic symmetry (Im3) of the Ce$_{1-x}$R$_{x}$Fe$_{4}$P$_{12}$ (R = Dy, Er, Yb, $x\lesssim 0.003$) skutterudite compounds. From the analysis of the ESR data the three CFPs, B4c, B6c and B6t were determined for each of these rare-earths at the Ce$^{3+}$ site. The field and temperature dependence of the measured magnetization for the doped crystals are in excellent agreement with the one predicted by the CFPs Bnm derived from ESR.Comment: 7 pages, 5 figures, to appear in PR

Patogénesis de la enfermedad de newcastle en la familia Psittacidae.

El Newcastle es una enfermedad especIfica y altamente contagiosa que afecta a los pollos, pavos y otras ayes domésticas, lo mismo que algunas especies de ayes silvestres, siendo de gran importancia económica para la industria avIcola nacional. El espectro de huéspedes del virus de Ia enfermedad de Newcastle que incluye no solo a ayes domésticas y salvajes sino al hombre y otros mamiferos, aumenta su peligro potencial y actual. La alta resistencia del virus a condiciones ambientales adversas y la facilidad con que se propaga especialmente en los exudados, excretas y despojos de las ayes infectadas juegan un papel importante en Ia diseminación de la enfermedad de Newcastle. Los objetivos de este trabajo fueron establecer la patogenesis de la enfermedad de Newcastle en loros, averiguar el papel de portadores que los bros puedan jugar en la diseminación de la enfermedad de Newcastle, y estudiar La respuesta inmunitaria en bros a cepas patogenas y vacunales de Newcastle de pollos

Patogénesis de la enfermedad de newcastle en la familia Psittacidae.

Se hizo un estudio sobre la patogénesis de la enfermedad de newcastle en la familia Psittacidae, especialmente sobre el papel que pueda desempeñar en la diseminación y perpetuación del virus. Se inocularon 70 loros (Amazona achrocephala), negativo a la prueba inhibición de la hemaglutinación utilizando diferentes vías y dosis de virus patógeno de la enfermedad newcastle encontrando que la vía más efectiva para reproducir la enfermedad fué la intramuscular con 100.000 dosis letal embriones pollo 50. Los loros presentaron síntomas y lesiones características de la enfermedad. El virus se recobró de los animales hasta 15 días post-inoculación; los anticuerpos se detectaron a partir del décimo día después de inoculados hasta 60 días, fecha en la cual se suspendió el muestreo encontrando disminución progresiva de los títulos de HIMaestría en CienciasMaestrí